add flags to desugar to emit metadata that can be used for double-checking correctness of default and static interface desugaring.

RELNOTES: none

PiperOrigin-RevId: 170779637

1 files changed, 29 insertions, 11 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/desugar/InterfaceDesugaring.java b/src/tools/android/java/com/google/devtools/build/android/desugar/InterfaceDesugaring.java
index 6bac9edb26..0f03236e72 100644
--- a/src/tools/android/java/com/google/devtools/build/android/desugar/InterfaceDesugaring.java
+++ b/src/tools/android/java/com/google/devtools/build/android/desugar/InterfaceDesugaring.java
@@ -42,9 +42,9 @@ class InterfaceDesugaring extends ClassVisitor {
   static final String COMPANION_METHOD_TO_TRIGGER_INTERFACE_CLINIT_NAME = "$$triggerInterfaceInit";
   static final String COMPANION_METHOD_TO_TRIGGER_INTERFACE_CLINIT_DESC = "()V";
 
-  static final String COMPANION_SUFFIX = "$$CC";
   static final String INTERFACE_STATIC_COMPANION_METHOD_SUFFIX = "$$STATIC$$";
 
+  private final DependencyCollector depsCollector;
   private final ClassReaderFactory bootclasspath;
   private final GeneratedClassStore store;
   private final boolean legacyJaCoCo;
@@ -52,13 +52,18 @@ class InterfaceDesugaring extends ClassVisitor {
   private String internalName;
   private int bytecodeVersion;
   private int accessFlags;
+  private int numberOfDefaultMethods;
   @Nullable private ClassVisitor companion;
   @Nullable private FieldInfo interfaceFieldToAccessInCompanionMethodToTriggerInterfaceClinit;
 
   public InterfaceDesugaring(
-      ClassVisitor dest, ClassReaderFactory bootclasspath, GeneratedClassStore store,
+      ClassVisitor dest,
+      DependencyCollector depsCollector,
+      ClassReaderFactory bootclasspath,
+      GeneratedClassStore store,
       boolean legacyJaCoCo) {
     super(Opcodes.ASM5, dest);
+    this.depsCollector = depsCollector;
     this.bootclasspath = bootclasspath;
     this.store = store;
     this.legacyJaCoCo = legacyJaCoCo;
@@ -73,15 +78,26 @@ class InterfaceDesugaring extends ClassVisitor {
       String superName,
       String[] interfaces) {
     companion = null;
+    numberOfDefaultMethods = 0;
     internalName = name;
     bytecodeVersion = version;
     accessFlags = access;
+    if (isInterface()) {
+      // Record interface hierarchy.  This helps avoid parsing .class files when double-checking
+      // desugaring results later using collected dependency information.
+      depsCollector.recordExtendedInterfaces(name, interfaces);
+    }
     super.visit(version, access, name, signature, superName, interfaces);
   }
 
   @Override
   public void visitEnd() {
     if (companion != null) {
+      // Record classes with default methods.  This increases precision when double-checking
+      // desugaring results later, without parsing .class files again, compared to just looking
+      // for companion classes in a given desugared Jar which may only contain static methods.
+      depsCollector.recordDefaultMethods(internalName, numberOfDefaultMethods);
+
       // Emit a method to access the fields of the interfaces that need initialization.
       emitInterfaceFieldAccessInCompanionMethodToTriggerInterfaceClinit();
       companion.visitEnd();
@@ -185,6 +201,7 @@ class InterfaceDesugaring extends ClassVisitor {
               name,
               internalName,
               desc);
+          ++numberOfDefaultMethods;
           abstractDest =
               super.visitMethod(access | Opcodes.ACC_ABSTRACT, name, desc, signature, exceptions);
         }
@@ -228,7 +245,7 @@ class InterfaceDesugaring extends ClassVisitor {
       // Rename lambda method to reflect the new owner.  Not doing so confuses LambdaDesugaring
       // if it's run over this class again. LambdaDesugaring has already renamed the method from
       // its original name to include the interface name at this point.
-      suffix = COMPANION_SUFFIX;
+      suffix = DependencyCollector.INTERFACE_COMPANION_SUFFIX;
     } else if (isStatic) {
       suffix = INTERFACE_STATIC_COMPANION_METHOD_SUFFIX;
     } else {
@@ -238,7 +255,7 @@ class InterfaceDesugaring extends ClassVisitor {
   }
 
   static String getCompanionClassName(String interfaceName) {
-    return interfaceName + COMPANION_SUFFIX;
+    return interfaceName + DependencyCollector.INTERFACE_COMPANION_SUFFIX;
   }
 
   /**
@@ -329,8 +346,8 @@ class InterfaceDesugaring extends ClassVisitor {
         name = normalizeInterfaceMethodName(name, isLambda, opcode == Opcodes.INVOKESTATIC);
         if (isLambda) {
           // Redirect lambda invocations to completely remove all lambda methods from interfaces.
-          checkArgument(
-              !owner.endsWith(COMPANION_SUFFIX), "shouldn't consider %s an interface", owner);
+          checkArgument(!owner.endsWith(DependencyCollector.INTERFACE_COMPANION_SUFFIX),
+              "shouldn't consider %s an interface", owner);
           checkArgument(!bootclasspath.isKnown(owner)); // must be in current input
           if (opcode == Opcodes.INVOKEINTERFACE) {
             opcode = Opcodes.INVOKESTATIC;
@@ -344,7 +361,7 @@ class InterfaceDesugaring extends ClassVisitor {
                 name);
           }
           // Reflect that InterfaceDesugaring moves and renames the lambda body method
-          owner += COMPANION_SUFFIX;
+          owner += DependencyCollector.INTERFACE_COMPANION_SUFFIX;
           String expectedLambdaMethodName = LambdaDesugaring.uniqueInPackage(owner, name);
           checkState(
               name.equals(expectedLambdaMethodName),
@@ -355,14 +372,14 @@ class InterfaceDesugaring extends ClassVisitor {
           itf = false;
         } else if ((opcode == Opcodes.INVOKESTATIC || opcode == Opcodes.INVOKESPECIAL)
             && !bootclasspath.isKnown(owner)) {
-          checkArgument(
-              !owner.endsWith(COMPANION_SUFFIX), "shouldn't consider %s an interface", owner);
+          checkArgument(!owner.endsWith(DependencyCollector.INTERFACE_COMPANION_SUFFIX),
+              "shouldn't consider %s an interface", owner);
           if (opcode == Opcodes.INVOKESPECIAL) {
             // Turn Interface.super.m() into Interface$$CC.m(receiver)
             opcode = Opcodes.INVOKESTATIC;
             desc = companionDefaultMethodDescriptor(owner, desc);
           }
-          owner += COMPANION_SUFFIX;
+          owner += DependencyCollector.INTERFACE_COMPANION_SUFFIX;
           itf = false;
         }
       }
@@ -384,7 +401,8 @@ class InterfaceDesugaring extends ClassVisitor {
     @Override
     public void visitFieldInsn(int opcode, String owner, String name, String desc) {
       if ("$jacocoData".equals(name)) {
-        checkState(!owner.endsWith(COMPANION_SUFFIX), "Expected interface: %s", owner);
+        checkState(!owner.endsWith(DependencyCollector.INTERFACE_COMPANION_SUFFIX),
+            "Expected interface: %s", owner);
         owner = getCompanionClassName(owner);
       }
       super.visitFieldInsn(opcode, owner, name, desc);